Article of manufacture for wrist-watch crystals



J. PIEF 1,812,367

ARTICLE OF MANUFACTURE FOR WRIST WATCH CRYSTALS June 30, 1931 Filed Feb.

.gqiug FIG. I.

FIG. 4.

a INVENTOR Patented June 30, 1931 PATENT OFFICE JOHN PIEF, OF OKLAHOMA CITY, OKLAHOMA ARTICLE OF MANUFACTURE FOR WRIST-WATCH CRYSTALS Application filed February 4, 1929. Serial No. 337,479.

My invention relates to a wrist-watch crystal as an article of manufacture.

The objects of my invention are to produce a device of the class described which will be new, and useful; which will be novel, practical and of utility; which will be strong, durable and economical; which will last long er than the ordinary and usual wrist-watch crystal; which will have the appearance and effect of a jeweled wrist-watch crystal; which will concentrate and refract rays through the face of the watch crystal toward and surrounding the figures on the face of the watch giving better vision to the numerals and hands of the watch; which will be thicker than the usual wrist-watch crystal; which will have the appearance of being much thicker than it really is; which will with stand dropping of the watch on the crystal without the breaking of the crystal; which will produce the effect of being able to see clearly the face of the watch and characters thereon from every angle at which the crystal is viewed except through the small beveled corners; which has the effect of making the figures on the face of the watch appear larger than they really are; which will be attractive and beautiful; which will be made of optical glass giving clear vision; which will ac- 'co1nplish all of the purposes for which it is intended.

At present the ordinary small sizes in which most of the wrist-watches are necessarily made, prevent their having large and "thick crystals thereon. Almost everyone having had experience with the use of wristwatch crystals thereon knows the frequency with which the crystals are broken, and of .the almost constant necessity of their being 40 replaced by new ones; and that unless these are effectively and correctly replaced the new one put in lasts but a short time. Some effort has been made to compensate the break- .ing quality and frequent replacement of the crystals by using what is sometimes termed,

non-breakable crystals, formed of mica, celluloid, and the like. These have not proven satisfactory. They are cheap looking, and are likely to be bent in on the hands of the watch causing injury to the hands and face and possibly other working parts of the watch. They become scratched easily which obstructs the vision therethrough. They may be easily destroyed by fire.

My invention overcomes the danger of breakage by not only being heavier and thicker than the usual watch crystal, but by the fact that the shape thereof tends to strengthen the crystal. It may be dropped from waist high upon concrete with no danger of breaking. As it is optical glass it is of course practically immune from damage by fire, such as from lighted cigarettes, and the like. My invention has the appearance of being a jewel instead of a watch crystal, which makes it very much more attractive than the pres entcrystal. It is in fact beautiful.

With these and other objects in view as will more fully appear from my invention consists in the construction, novel features, and combination of parts hereinafter more fully described, pointed out in the claims hereto appended, and illustrated in the accompanying one-sheet drawing, of which,

Figure 1 is a plan. view of the watch crystal; Fig. 2 is a section along the line of 2- -2 of Fig. 1; Fig. 3 is a section along the line of 33 of Fig. 1; Fig. 4 is a plan view of a watch face with the crystal thereover; Fig.

5 is a perspective View of the watch crystal showing the jewel effect of the crystal on the watch.

Like characters of reference designate like parts in all the figures.

It is understood that various changes in the 35 form, proportion, size, shape, weight and other details of construction, within the scope of my invention may be resorted to without departing from the spirit or broad principle of my invention and without sacrificing any of the advantages thereof; and it is also understood that the drawings are to be interpreted as being illustrative and not restrictive.

A practical embodiment of the invention as illustrated in the drawings includes: It will be seen in Figures 1, 4 and 5 that the outer edges of my crystal, which is made out of optical glass, form a rectangle, bounded by lines A B, B-C, CD and A-D, the

corners of which are represented as A, B, C and 'D, which fit into the grooves formed therefor in the frame or case of a watch. The under surface of said crystal is, at the edges represented by said lines, AB, BC, CD and AD perfectly fiat. If placed bottom downward upon a flat table, said crystal would touch said table at all points represented by said lines AB, B C, C-D, and AD. The underside of said crystal surrounding its center is circularly concave from all directions to a point E in the center of same, as may better be seen in Figs. 2 and 3. 'The upper surface of said crystal is invertedly concave from points 1, 2, 3 and 4 to point E in the center of crystal. The, outer, side edges of said crystal are convex from line AB to curved line 12, and from line B-C to curved line 2-3, also from line C-D to curved line 34 and also from line AD, to curved line 41. It will be noted that lines 1-2, 2+3, 34, and 4-1 are slightly curved outwardly. It will also be noted that the corners formed at lines A1, 13-2, C 3 and Dl, are beveled from points X, to respective corners A, B, C and D, forming a flat surface at each corner of said crystal, which is tapered to an acute triangular shape as shown at 5. This may be better seen in Figs. 1, 4: and 5. It may readily be seen that the crystal is thinner at point E than at any other point, and that its highest points are represented by curved lines 1-2, 2-45, 34 and 4.-1.

Obviously, the invention is susceptible of embodiment in forms other than that which is illustrated in, the accompanying drawings and described herein, and applicable for the uses and purposes other than as detailed, and I therefore consider as my own all such modifications and adaptations and other uses of the form of the device herein described as fairly fall within the scope of my invention.

Having thus described my invention what is claimed and desired to be secured by Letters Patents, is; I 1

1. As an article of manufacture, a wristwatch crystal, as described, comprising a'rectangularly shaped body having oppositely concave surfaces on its lower and upper faces and having outer side and end convex edges its bottom edge portion fiat, said outer convex edges having a small plane surfaced triangularly shaped beveled portion at the meeting corners of said. side and end convex edges, said crystal being adapted to fit over a wristwatch face.

2. As an article of manufacture, a wrist-' watch crystal, as described, comprising a rectangularly shaped body having a portion of 1ts under surface circularly concave suI-' the external meeting corners, its bottom edge portion fiat, a portion at each of said corners upon its upper edge portion having a plane beveled triangularly shaped surface,

said crystal being adapted to fit over a wristwatch face.

3. As an article of manufacture, a Wristwatch crystal, as described, comprising a rectangularly shaped body having a portion of its under surface circularly concave surroundingits center, having a portionof its upper surface oppositely uniformly concave surrounding its center, the radius length of said two oppositely concave surfaced portions being equal, said bodyhaving the upper portions of its side edges uniformly convex to a point adjacent the external meeting corners, its bottom edge portion flat, a ortion of each of said cornersihaving a plane eveled triangularly shaped upper surface, said crystal being adapted to fit over a wristwatch face. i

4. As an article of manufacture, a wrist- 7 said body having upperv portions of its side edges uniformly convex to a point adjacent the external meeting corners, its bottom edge portion flat, a portion of each of said corners having a plane beveled triangularly shaped upper surface, said crystal being adapted to fit over a wrist-watch face. o 7

JOHN PIEF.

rounding its center, having a portion of'its upper surface oppositely uniformly concave surrounding its center, having portions of 1ts 1 upper side edges convex to a point adjacent 

